Grinding machine



Oct. 19 1926. I 1,603,667

A. M. DRAKE ET AL GRINDING MACHINE Filed Jan. 11, 1924 2 Sheets-Sheet 1l 72%732237'. .HZden m Eralfe WEI d0 7. GU82 orvzqy Oct. 19 1926.

A. M. DRAKE ET AL GRINDING MACHINE Filed Jan. 11, 1924 2 Sheets-Sheet 2jar/72357.- .ZIZdeTa 772 ,DraKe lines H and 5 Patented a. 19, 1926.UNITED STATES PATENT OFFICE.

ALDEN M. DRAKE AND WALDO J'. GUILD, OF WORCESTER, MASSACHUSETTS, AS-

SIGNORS TO THE HEALD MACHINE COMPANY, OF WORCESTER, MASSACHUSETTS,

A CORPORATION OF MASSACHUSETTS.

GRINDING MACHINE.

Application filed January 11, 1924.- Serial No. 685,577.

The present invention relates to grinding machines and contemplatescertain improvements and refinements in the automatic mechanism whichprocures relative reciprocatory movement betwecn'the work and thegrinding wheel,the objects being (1) to facilitate a rapid withdrawal ofthe wheel from the work, or vice versa, when it is desired to giveaccess to the work for gauging or for replacement, and (2) to makeprovision, at the same time, for a short with drawal movement, withoutincrease of speed, in order to subject the wheel at intervals to adressing and truing operation.

The several features of the invention, by which the above and otherobjects are attained, are fully set forth hereinafter, reference beinghad to the accompanying drawings in which- Fig. 1 is a view in sideelevation of so much of a grinding machine as is necessary to disclosethe invention.

Fig. 2is an enlarged detail view of the arrangement of dogs or stopsshown in Fig. 1.

Fig. 3 an end view of the parts shown in Fig. 2.

Figs. 4 and 5 are sectional views on the 5 respectively, of Fig. 2.

Fig. 6 is a fragmentary detail View of the latch connection shown in Big. 2.

Like reference characters refer to like parts in the different figures.

Referring first to Fig. 1, the invention is here shown by way of examplein connection with the reciprocatory table or carriage 1 of an internalgrinding machine. In such a machine, either the grinding wheel or thework to be ground may be carried on the table 1, the reciprocations ofthe latter being utilized in either case to produce a relativetraversing movement between the grinding wheel and the work. As hereshown, the table, 1 supports and carries a wheel head 2 of ordinaryconstruction,the work supporting head 3 being carried by a bridge 4which 5 ans the slideways provided by the machine frame for the movementof the table 1. Back and forth movement of the table 1, to cause therotating grinding wheel 5 to make the required interior traverse of therotating work piece 6, may be imparted in any well known manner, as forinstance, by the use of the fluid pressure controlling and reversingmechanism which forms the subject matter of the copending application ofHeald and Guild, Serial No. 629,882, filed April 4, 1923. Suchmechanism, or its equivalent, forms no part of the present invention anda detailed description thereof is therefore unnecessary; it issufficient'to note, for therpurposes of the resent application, that thetype of drive a opted for the actuation of the table 1, be it hydraulicdrive, or gear drive, or any other type, procures the reversal of thetable at each end of its working stroke by the useof spaced adjustabletable dogs 7 and 8, adapted to alternately engage and move an interposedmember 9, whose position controls the direction of tabl travel.

In the normal operation of the machine, with the grinding wheel 5 incontact with the work 6, the table 1 will be reversed at each successiveengagement of the member 9 by the dogs 7 and 8, which dogs obvious- 1yare spaced apart on said table a distance substantially corresponding tothe'workin stroke of the grinding wheel, i. e., the lengt of the hole inthe work 6. In the operationof an internal grinding machine such as hereshown, there 1s frequent necesslty for interrupting the grindingoperation in order that the operator may size or plug the hole which isbeing ground; such action by the operator, and also the removal of workfrom the machine and the introduction of a new piece, requires the wheeland the Work to be separated axially or longitudinally, in orderto giveaccess to said work. In the machine herein illustrated, this separationis obtained by continuing the movement of the table 1 to the right, andfor this purpose, the dog 8 is so constructed that it can be passed overthe member 9, whenever desired, without efiect on said member, thelatter remaining in the position illustrated in Fig. 1, which is theposition given it by the dog 7, on the preceding stroke of the table 1,to inaugurate'movement of said table to the right.

To this end, the dog 8 is made in the form of a lever pivoted at 10 toits carrying block 11,with said pivoted end normally hearing by gravityagainst a stop or ledge 12 on said block, whereby to dispose the otheror striking end of said dog 8 in position to engage the member 9. Theelevation of the striking end of dog 8, to cause it to passinopertreadle operation, bein atively over the member 9, is accomplishedby interposing in the path of said dog, just before it reaches themember 9, the upwardly inclined cam surface 13 of a member 14, which iscarried by a vertically slidable rod 15 assing through a bracket 16 onthe front 0 the machine. The rod 15 normally occupies the inoperativepositionillustrated in Fig. 2, with the cam surface 13 just below andout of the path of the dog 8; by its connection at 17,190 a treadle 18pivoted at 19 to the base of the machine, the rod 15 is adapted to beelevated by foot pressure applied to said treadle, and this movementwhich, it is to be particularly noted, leaves both of the operatorshands free to give such attention as may be desired to the work, resultsin the dog 8 riding up the cam surface 13, so as to clear the top of themember 9. This obviously prevents the reversal of the table 1, whichwould otherwise take place at its right hand limit of workingreciprocation,-thc right hand movement being continued so as to withdrawthe grinding wheel altogether from the work zone at an accelerated rateof movement, as hereinafter described. 1

If desired, the above described interposition of the cam surface 18 maybe accomplished by hand rather than by operation of the foot treadle 18.To this end, the member 14 is equipped with a projecting handle 20, inconvenient position to be seized and drawn upwardly by the operatoralong with said member and its attached rod 15,-the limit of upwardmovement, both in the case of hand operation and determined by a collar21 on rod 15, whic i engages the under side of-the bracket 16. To adaptthe above described mechanism to machines whose bases are elevated atdifferent levels from the level at which the operator stands, thetreadle 18 is made in the form. of a bell crank lever; with a footengaging portion 22 on each side. If the operator stands on thesupporting floor, the treadleis so disposed as to slope its longer armdownwardly, as shown in full lines in Fig. 3; on the other hand, if anoperating platform, above the floor level, is used, said treadle isreversed, as shownby the broken lines in The carrying block'll and thepivoted dog 8 support also an elongated bar or cam 23, Fig. 2, the righthand end of which is s aced from the striking end of dog 8 by a istanceslightly less'than that between the top of member 9 and a cam roller 24,Fig. 1, carried by the end of an arm 25. In the normal workingreciprocations of the table 1, when the grinding wheel is in contactwith the work, the roller 24 is not reached b the bar or cam 23, sincethe dog 8 will a ways strike the member 9 to reverse the table, when thecam and roller are still a little distance apart. However, when the dog8 is lifted by the operator, as above described, to pass over the member9 and thereby inaugurate a non-working movement of the table 1 to theright, the bar or cam 23 will engage the roller 24 to depress the arm25. This depression of the arm 25 is availed of to produce an increasedspeed of travel for the table 1, either in the manner described in theaforesaid copending application of Heald and Guild, or in any other wellknown manner. The purpose of this is to automatically accomplish theright hand non-working movement of table 1 at the maximum speed,irrespective of the speed selected for the working movement when thegrinding wheel is in contact with the work; this eliminates anyunnecessary loss of time in movin the grinding wheel away from the work,since the bar or cam 23 maintains its engagement with the roller 24throughout the entire withdrawal movement, thus automaticallymaintaining the high speed table travel until the table is brought torest at the end of said right hand movement, as fully described in theaforesaid application of Heald and Guild.

While such high speed table travel is especially advantageous when freeaccess to the work 6 is desired, the opposite of this is true in otherinstances r uiring withdrawal of the grinding whee 5 from the work, aswhen subjecting said wheel to the action of a dressing or truing device26, Fig. 1, which ma be carried by the usual bridge 27. Such ressin andtruing, which is frequently resorte to in the operation of grinding,requires only a limited withdrawl movement of the wheel from the work,and is an operation wherein it would be most undesirable for thetraverse of the wheel to take place at high speed. To fulfill theseconditions therefor, provision must be made for a wholl difierentcharacter of wheel withdrawal rom that above described, which involvesthe inoperative passage of dog 8 over member 9 and the ensuing prolongedright hand movement of table 1 at maximum speed; the withdrawal fordressing or ti'uing, which must be selectively available to the operatorof the machine along with the first described withdrawal, involves onlya short right hand movement of the table 1, and this at a speed nohigher than the relativel slow traverse of the wheel in contact wit thework.

To this end, it is proposed to make the dog 8 readily shiftable to theleft from its normal working sition, so as to give an increase, whendesired, in the right hand throw or stroke of table lsuflicient to carrythe wheel 5 past the dresser 26. Instead of securing the block 11' ofdog 8 directly to the table, as is done in the ease of the dog 7, saidblock 11 is operatively and removably c,on-, nected, in spaced relation,to a block 28, the latter, in common with the block 29 of dog 7, havinthe usual set screw device 30 for adjustab y securing it at any desiredposition longitudinally of the edge of table 1. The connection betweenthe block 28 and the block 11 is a latch lever 31, pivoted at 32 to theblock 11, and having a shoulder 33 in its free end which abuts aprojection or boss 34 on the, block 28, with the other side of saidbossengaged by ,a handle 35 of said lever. In this position of theparts, the latch lever 31 holds the block 11 in definite spaced relationtothe block 28, and in adjusting the dog 8 to procure any desiredworking stroke of the table, the block 28, instead of the block 11, isthe partthat is moved and that is secured in the desired position ofadjustment along the edge of the table.

When the operator desires to have the grinding wheel 5 carried past thedresser 26, in order to true the surface of said wheel, he simply seizesthe handle v35 on the latch lever 31 and lifts the shoulder 33 andhandle 35 away from boss 34; this makes the block 11 freely slidable, tobe drawn by the operator or pushed by the member 9 to the left, untilthe adjusting screw 8 of dog 8 abuts a projection 28 of block 28. Thisaction increases the right hand throw of table 1 by postponingtheoperative pressure of dog 8 against member 9, and theamount of suchincrease is sutficient to carry the grinding wheel 5 past the dresser26. However, no increase in the speed of said table is produced, sincethe bar or cam 23, being secured to the block 11, moves to the left withit and does not reach the roller 24, notwithstanding the increased righthand travel of the table. After the grinding wheel 5 has been passed asufficient number of times in contact with the dresser 26, the operatorpushes the latch lever 31 to the right and restores the operativeconnection between the notch 33 and the boss 34, thereby holding theblocks 11 and 28 in the predetermined s aced relation that causes thewheel 5 to ma e its regular workin stroke; The ivotal connection of thelate lever 31 to t e block 11 may be made at any one of a plurality ofdifierent holes 36 in said block, in order to vary, as desired, the sacing' between blocks 11 and 28, and ther y give greater or lessamplitude to the slow speed withdrawl movement availed of for thepurpose of dressingthe wheel. Obviousl the latch lever may be ivoted tothe b ock 28, instead ofto the lock 11, in which case the latchengagement would be with the block 11.

We claim, p

1. In apparatus of the class described, a reciprocatory table, a membershiitable in opposite directions to procure the reversals in themovement of said tablejadjustable stops carried by said table forengaging and shifting said member, one of said stops being pivotallymounted and maintained by gravity in its operative position, and fixedposition operator controlled means for interposing a cam surface in thepath ofsaid stop, to swing it into inoperative position.

2. In a machine of the "class described, a reciprocatory table,adjustable stops on said table for reversing the movement of the tableat each end of its travel, and a treadle, pivoted at the base of themachine, and adapted'whenactuated to render one of said stopsinoperative, said treadle being of bell-crank form, whereby its reversalaccommodates it to machine bases at different heights from the operatingfloor.

3. In apparatus of the class described, a reciprocatory table, a membershiftable in opposite directions to procure'the reversals in themovement of said table, adjustable stops carried by said table forengaging and shifting said member, one of said stops being slidable awayfrom th other stop, to temporarily increase the travel of said table,together with a latching member which automatically identifies theprevious position of the stop and checks it there.

4. In apparatus of the class described, a reciprocatory table, a membershiftable' in opposite directions to procure the reversals in themovement of said table, a block ad- 1 justably secured'tosaid table, anda pair of stops carried by said table for engaging and shifting saidmember, one of said stops being adjustably secured to said table, andmeans for releasably holding the other in predetermined spaced relationto said block.

5. In a grinding machine, a reciprocatory table, a member shiftable inopposite directions to procure the reversals in the movement of saidtable, and a pair of adjustable stops carried by said table for engagingand shifting said member in the normal movements of said table, incombination with means to remove one of said stops from the path of saidmember, thereby procuring the movement of said table to nonworkingposition, and means operable'from a fixed position to delay the oeration of said member by said stop, there y increasing the throw ofsaid table in one direction.

6. In a grinding machine, a reciprocatory table, a member shiftable inopposite directions to procure the reversals in the movement of saidtable, and a pair of adjustable stops carried by said table for en.gaging and shifting said member in the normal working movements of saidtable, in combination with means for procuring the travel of said'tableat increased speed away [from working position, by passing said memberwith one of said stops, and means operable from a fixed position forincreasing the Working throw of said table, without increasing itsspeed, by shifting said stop.

7. In a grinding machine, a reciprocating table, a stop carried by saidtable and operable on a shiftable member to limit the table movement inone direction, a member moving with said stop and rendered operativewhen said shiftable member is passed by said stop, to increase the speedof said table on its ensuing non-working travel, and means for shiftingsaid stop, which then operates said shiftable member, to increase theworking throw of said table without increasing its speed.

8. In a grinding machine, a table carrying the grinding wheel, andadapted to reciprocate, to traverse the work with said wheel,

.a stop carried by said table for limiting the travel of the wheel inone direction, means for rendering said .stop inoperative, to procurecomplete withdrawal of said Wheel from said path, means moving with saidstop for increasing the speed of said table on said withdrawal movement,and

means for shifting said stop, to increase said path of travel, withoutincreasing the speed of said table ciprocating table on which one ofsaid parts is carried, a reversing element to cause the reciprocationsof the table to be reversed, a pair of dogs carried by the table toactuate the reversing element, a clamping member adapted to beadjustably clamped to said table, and a bar with a shoulder thereon,said bar engaging said clamping member and one of said dogs, whereby oneof said dogs can be disengageably held a fixed distance from saidclamping member. 11. In a grinding machine, a rotary grinding wheel anda work holding device, a reciprocating table on which one of said partsis carried, a reversing element to cause the reciprocations of the tableto be reversed, a pair of dogs carried by the table to actuate thereversing element, an adjustable clamping member, one of said dogs beingslidable on ways, and releasable means holding said slidable dog a fixeddistance away from said clamping member.

12. In a grinding machine, a rotary grinding wheel and a work holdingdevice, a reciprocating table on which one of said parts is carried, areversing element to cause the reciprocations of the table to bereversed, a pair of dogs carried by the table to actuate the reversingelement, a clamping member and a disengageable spacing member, one ofsaid dogs being slidable on ways and being releasably held on said waysa fixed distance away from said clamping member by said spacing member,whereby said dog may be held at said fixed distance or allowed toslidealong said ways to a predetermined point.

Dated this 22nd day of December, 1923.

ALDEN M. DRAKE. VVALDO J. GUILD.

